Cylinder deactivation and variable valve lift techniques are used to vary the power characteristics of internal combustion engines. Engines with cylinder deactivation capabilities are fuel efficient while still providing additional power when necessary. Improved fuel economy is achieved by deactivating a number of cylinders when the engine is under lower loads, effectively decreasing the displacement of the engine during these times. For example, four cylinders of an eight cylinder engine can be deactivated to halve the engine displacement and realize the improved fuel economy of a smaller displacement four cylinder engine. When larger loads are present, such as during periods of acceleration or traveling up hill, all eight cylinders are used to provide ample power until the higher load conditions subside.
Rather than entirely deactivating cylinders, variable valve lift systems allow the power characteristics of an engine to be changed during driving while continuing to utilize all of the cylinders. These systems can also provide improved fuel economy and may be used to provide other benefits in situations where it would be beneficial to dynamically change engine power characteristics. It would be beneficial to improve current cylinder deactivation and variable valve lift techniques.